(1) Field of the Invention
The present invention relates to a damping unit for film packing device, and more particularly, to a tension adjustable damping unit for film packing device.
(2) Description of the Prior Art
A conventional film packing device is used to wrap multiple layers of film to objects so as to protect the objects from scrape or rains. The conventional film packing device is shown in FIG. 6 and generally includes a base 60 which is connected with a mandrel 61 which is movable up and down relative to the base 60. A roll 70 of film is mounted to the mandrel 61 and the film 71 is pulled from the roll 70 to wrap around the objects. The objects are located on a rotatable support board and rotated to drag the film 71 to wrap around them. However, the shapes of the objects to be wrapped may not the same so that each point on the object is located at different distance from the mandrel 61. The tension of the film 71 is larger when the object is located closer to the mandrel 61 and smaller when the object is located far from the mandrel 61. The film 71 bends due to the gravity or even attached to each other if the object is located at a distance from the mandrel 61. Therefore, it is important to keep the film 71 with proper tension when packing the objects at different distances.
The present invention intends to provide a damping unit for film packing device wherein the speed of the rotation of the roll of the film can be adjusted so that when the film is dragged by the rotation of the objects, the tension of the film can be maintained.